This invention relates to inked ribbon cartridges used for storing inked ribbon in random folds in a housing before presenting it for printing and particularly to method and means for facilitating the feeding of such ribbon into a housing storing large quantities of ribbon in random folds.
With the advent of high speed printing, a need has arisen for minimizing ribbon replacement by storing large quantities of inked ribbon in a reservoir or housing at the site where printing is to take place and withdrawing it for printing as needed. One common way for storing inked ribbon is to provide an endless loop of ribbon and storing a substantial portion of it in a housing or reservoir except for that portion needed for immediate printing. It is common practice to confine the ribbon in a cartridge substantially the height of the ribbon such that it stands on edge and to stack the ribbon tightly in random folds in the cartridge. As the ribbon is withdrawn from the cartridge at one point for printing, it is fed back into the cartridge at another point for storage and reuse in printing. A common method for withdrawing ribbon from the outlet end of the reservoir and feeding it to an inlet end is to use pitch rollers. These may take the form of friction rollers for contacting the sides of the ribbon with sufficient pressure to perform the feeding and withdrawing functions without slippage. Reference can be made to U.S. Pat. No. 3,989,132 assigned to the common assignee and filed Aug. 26, 1974 for further details.
As the volume of the ribbon stored in any given reservoir is increased, internal ribbon pressure builds up in the reservoir, slowing the movement of ribbon away from the rollers and thus exposing the ribbon to higher levels of rubbing and scuffing by the rollers for longer periods of time. This not only reduces ribbon life substantially but also increases the likelihood that the ribbon may jam itself by attempting to follow a roller outside of the storage area instead of remaining within the reservoir.